1. Field of the Invention
The present invention relates to a method for manufacturing an organic electroluminescence panel.
2. Description of the Related Art
One of known organic electroluminescence panels has an organic electroluminescence element that is disposed on a glass substrate and that has a sandwich structure in which an organic luminescent layer is sandwiched between two electrodes. One of the two electrodes is a transparent electrode, in general, formed of indium tin oxide (ITO), to extract light from the organic luminescent layer. The outer surface of the organic luminescent layer is sealed. The organic luminescent layer emits light upon the application of a voltage by an external drive circuit.
Organic electroluminescence panels that include an organic electroluminescence element that emits light according to the above-mentioned principle have excellent legibility and produce various colors. Hence, the organic electroluminescence panels have been used in displays and display devices for use in onboard component stereo systems, mobile phones, and the like.
In a recently devised method, organic electroluminescence panels are manufactured in a multiple pattern. In this method, after organic electroluminescent components corresponding to a plurality of panels are formed on a single large substrate, the substrate is cut to manufacture a plurality of organic electroluminescence panels.
Japanese Patent Laid-Open No. 2003-249354 describes such a method for manufacturing an organic electroluminescence panel. This patent document addresses a problem which arises when cutting a substrate on which a protective layer is formed. During this severing procedure cracking or peeling of the protective layer may occur. More specifically, the protective layer is formed while a mask covers a cut line. After removal of the mask, the substrate is divided along the cut line on which no protective layer exists. The protective layer is formed to seal out water and oxygen.
However, in the method for manufacturing an organic electroluminescence panel according to Japanese Patent Laid-Open No. 2003-249354, the mask must be accurately placed on the cut line. In addition, the step of removing the mask after the formation of the protective layer complicates the manufacturing process.
To simplify the manufacturing process, a protective layer, should be formed over a plurality of organic electroluminescence element groups disposed on a large substrate, and the large substrate should be divided together with the protective layer.